Yttria-stabilized zirconia tetragonal ceramics have good biocompatibility and excellent mechanical properties. In particular, They have much higher fracture toughness compared to alumina ceramics. Since the 1990s, zirconia ceramics have been used as crown materials in dental fixed restoration. However, because of their poor light-transmission, zirconia ceramics are required to be veneered onto the crown during post-processing when restoration of anterior teeth for young patients is performed for aesthetic purpose so as to mimic the appearance of natural teeth. As a result, the abutment preparation space requirement is increased. In addition, since the thermal expansion coefficient difference between zirconia and the ceramic veneer is relatively large while the zirconia and the ceramic veneer do not have good chemical bonding, the bond strength between the ceramic veneer and the zirconia is poor and thus the ceramic veneer may peel off or break easily. It is indicated by the clinical study of zirconia all-ceramic teeth that the failure rate of zirconia-based all-ceramic teeth is above 10% after a use period of 5 years. In order to solve the problems of veneer breaking and large amount of ready-for-use dental articles, a full zirconia restoration with higher translucency and without any ceramic veneer is put in use. However, this restoration has a single light-transmission, thus it is difficult to mimic the appearance of natural teeth regarding its translucent end and thus is aesthetically poor.